Zeolite SSZ-23

ABSTRACT

A crystalline zeolite SSZ-23 is prepared using an adamantane quaternary ammonium ion as a template.

This is a continuation-in-part of Ser. No. 823,705, filed Jan. 29, 1986,now abandoned.

BACKGROUND OF THE INVENTION

Natural and synthetic zeolitic crystalline aluminosilicates are usefulas catalysts and adsorbents. These aluminosilicates have distinctcrystal structures which are demonstrated by X-ray diffraction. Thecrystal structure defines cavities and pores which are characteristic ofthe different species. The adsorptive and catalytic properties of eachcrystalline aluminosilicate are determined in part by the dimensions ofits pores and cavities. Thus, the utility of a particular zeolite in aparticular application depends at least partly on its crystal structure.

Because of their unique molecular sieving characteristics, as well astheir catalytic properties, crystalline aluminosilicates are especiallyuseful in such applications as gas drying and separation and hydrocarbonconversion. Although many different crystalline aluminosilicates andsilicates have been disclosed, there is a continuing need for newzeolites and silicates with desirable properties for gas separation anddrying, hydrocarbon and chemical conversions, and other applications.

Crystalline aluminosilicates are usually prepared from aqueous reactionmixtures containing alkali or alkaline earth metal oxides, silica, andalumina. "Nitrogenous zeolites" have been prepared from reactionmixtures containing an organic templating agent, usually anitrogen-containing organic cation. By varying the synthesis conditionsand the composition of the reaction mixture, different zeolites can beformed using the same templating agent. Use of N,N,N-trimethylcyclopentylammonium iodide in the preparation of Zeolite SSZ-15molecular sieve is disclosed in my copending Application Ser. No.437,709, filed on Oct. 29, 1982; use of 1-azoniaspiro [4.4] nonylbromide and N,N,N-trimethyl neopentylammonium iodide in the preparationof a molecular sieve termed "Losod" is disclosed in Helv. Chim. Acta(1974); Vol. 57, page 1533 (W. Sieber and W. M. Meier); use ofquinuclidinium compounds to prepare a zeolite termed "NU-3" is disclosedin European Patent Publication No 40016; use of 1,4-di(1-azoniabicyclo[2.2.2.]octane) lower alkyl compounds in the preparation of ZeoliteSSZ-16 molecular sieve is disclosed in U.S. Pat. No. 4,508,837; use ofN,N,N-trialkyl-1-adamantamine in the preparation of zeolite SSZ-13molecular sieve is disclosed in U.S. Pat. No. 4,544,538.

SUMMARY OF THE INVENTION

I have prepared a family of crystalline aluminosilicate molecular sieveswith unique properties, referred to herein as "Zeolite SSZ-23", orsimply "SSZ-23", and have found a highly effective method for preparingSSZ-23.

SSZ-23 has a mole ratio of an oxide selected from silicon oxide,germanium oxide, and mixtures thereof to an oxide selected from aluminumoxide, gallium oxide, iron oxide, boron oxide and mixtures thereofgreater than about 50:1 and having the X-ray diffraction lines of Table1 below. The zeolite further has a composition, as synthesized and inthe anhydrous state, in terms of mole ratios of oxides as follows: (0.1to 3.0)Q₂ O:(0.1 to 2.0)M₂ 0:W₂ 0₃ : (greater than 50)YO₂ wherein M isan alkali metal cation, W is selected from aluminum, gallium, iron,boron and mixtures thereof, Y is selected from silicon, germanium andmixtures thereof, and Q is an adamantane quaternary ammonium ion. SSZ-23zeolites can have a YO₂ : W₂ O₃ mole ratio greater than about 50:1. Asprepared, the silica:alumina mole ratio is typically in the range of70:1 to about 1500:1. Higher mole ratios can be obtained by treating thezeolite with chelating agents or acids to extract aluminum from thezeolite lattice. The silica:alumina mole ratio can also be increased byusing silicon and carbon halides and other similar compounds.Preferably, SSZ-23 is an aluminosilicate wherein W is aluminum and Y issilicon.

My invention also involves a method for preparing SSZ-23 zeolites,comprising preparing an aqueous mixture containing sources of anadamantane quaternary ammonium ion, an oxide selected from aluminumoxide, gallium oxide, iron oxide, boron oxide and mixtures thereof, andan oxide selected from silicon oxide, germanium oxide, and mixturesthereof, and having a composition, in terms of mole ratios of oxides,falling within the following ranges: YO₂ /W₂ O₃, 50:1 to 1500:1; and Q₂O/YO₂ 0.05:1 to 0.80:1; wherein Y is selected from silicon, germanium,and mixtures thereof, W is selected from aluminum, gallium, iron, boronand mixtures thereof, and Q is an adamantane quaternary ammonium ion;maintaining the mixture at a temperature of at least 100° C. until thecrystals of said zeolite are formed; and recovering said crystals.

DETAILED DESCRIPTION OF THE INVENTION

SSZ-23 zeolites, as synthesized, have a crystalline structure whoseX-ray powder diffraction pattern shows the following characteristiclines:

                  TABLE 1                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        8.15           10.85   100                                                    8.58           10.31   45                                                     9.50           9.31    55                                                     10.55          8.39    40                                                     17.60          5.04    45                                                     18.54          4.79    80                                                     19.65          4.52    65                                                     20.06          4.43    65                                                     21.53          4.13    100                                                    22.16          4.011   50                                                     22.72          3.914   70                                                     24.87          3.580   45                                                     ______________________________________                                    

Typical SSZ-23 aluminosilicate zeolites have the X-ray diffractionpattern of Tables 2-6 below. The X-ray powder diffraction patterns weredetermined by standard techniques. The radiation was the K-alpha/doubletof copper and a scintillation counter spectrometer with a strip-chartpen recorder was used. The peak heights I and the positions, as afunction of 2θ where θ is the Bragg angle, were read from thespectrometer chart. From these measured values, the relativeintensities, 100I/I_(o), where Io is the intensity of the strongest lineor peak, and d, the interplanar spacing in Angstroms corresponding tothe recorded lines, can be calculated. The X-ray diffraction pattern ofTable 1 is characteristic of SSZ-23 zeolites. The zeolite produced byexchanging the metal or other cations present in the zeolite withvarious other cations yields substantially the same diffraction patternalthough there can be minor shifts in interplanar spacing and minorvariations in relative intensity. Minor variations in the diffractionpattern can also result from variations in the organic compound used inthe preparation and from variations in the silica-to-alumina mole ratiofrom sample to sample. Calcination can also cause minor shifts in theX-ray diffraction pattern. Notwithstanding these minor perturbations,the basic crystal lattice structure remains unchanged.

After calcination the SSZ-23 zeolites have a crystalline structure whoseX-ray powder diffraction pattern shows the following characteristiclines as indicated in Table 2 below.

                  TABLE 2                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        8.17           10.82   100                                                    8.50           10.40   25                                                     9.45           9.36    100                                                    10.56          8.38    45                                                     17.78          4.99    10                                                     18.58          4.78    20                                                     19.63          4.52    15                                                     20.05          4.43    10                                                     21.58          4.118   15                                                     22.12          4.019   10                                                     22.56          3.941   10                                                     24.90          3.576   10                                                     ______________________________________                                    

SSZ-23 zeolites can be suitably prepared from an aqueous solutioncontaining sources of an alkali metal oxide, an adamantane quaternaryammonium ion, an oxide of aluminum, gallium, iron, boron or mixturesthereof, and an oxide of silicon or germanium, or mixture of the two.The reaction mixture should have a composition in terms of mole ratiosfalling within the following ranges:

    ______________________________________                                                     Broad   Preferred                                                ______________________________________                                        YO.sub.2 /W.sub.2 O.sub.3                                                                    50-1500   70-1500                                              OH.sup.- /YO.sub.2                                                                           0.125-0.90                                                                              0.20-0.50                                            Q/YO.sub.2     0.05-0.80 0.10-0.40                                            M.sup.+ /YO.sub.2                                                                            0.03-0.30 0.05-0.20                                            H.sub.2 O/YO.sub.2                                                                           20-300    40-80                                                Q/Q + M.sup.+  0.50-0.90 0.67-0.80                                            ______________________________________                                    

wherein Q is an adamantane quaternary ammonium ion, Y is silicon,germanium or both, and W is aluminum, gallium, iron, boron or mixturesthereof. M is an alkali metal, preferably sodium or potassium. Theorganic adamantane compound which acts as a source of the adamantanequaternary ammonium ion employed can provide hydroxide ion.

When using the adamantane quaternary ammonium hydroxide compound as atemplate, it has also been found that purer forms of SSZ-23 are preparedwhen there is an excess of the adamantane quaternary ammonium hydroxidecompound present relative to the amount of alkali metal hydroxide andthat when the OH⁻ /SiO₂ molar ratio is greater than 0.40, then M⁺ /SiO₂molar ratio should be less than 0.20.

The adamantane quaternary ammonium ion component Q, of thecrystallization mixture, is derived from an adamantane quaternaryammonium compound. Preferably, the adamantane quaternary ammonium ion isderived from a compound of the formula ##STR1## wherein each of Y₁ Y₂and Y₃ independently is lower alkyl and most preferably methyl; A⊖ is ananion which is not detrimental to the formation of the zeolite; and eachof R₁, R₂, and R₃ independently is hydrogen, or lower alkyl and mostpreferably hydrogen; and ##STR2## wherein each of R₄, R₅ and R₆independently is hydrogen or lower alkyl; and most preferably hydrogen;each of Y₁, Y₂ and Y₃ independently is lower alkyl and most preferablymethyl; and A⊖ is an anion which is not detrimental to the formation ofthe zeolite;

The adamantane quaternary ammonium compounds are prepared by methodsknown in the art.

By lower alkyl is meant alkyl of from about 1 to 5 carbon atoms.

A⊖ is an anion which is not detrimental to the formation of the zeolite.Representative of the anions include halogen, e.g., fluoride, chloride,bromide and iodide, hydroxide, acetate, sulfate, carboxylate, etc.Hydroxide is the most preferred anion. It may be beneficial toion-exchange, for example, the halide for hydroxide ion, therebyreducing or eliminating the alkali metal hydroxide quantity required.

The reaction mixture is prepared using standard zeolitic preparationtechniques. Typical sources of aluminum oxide for the reaction mixtureinclude aluminates, alumina, and aluminum compounds such as AlCl₃ andAl₂ (SO₄)₃. Typical sources of silicon oxide include silicates, silicahydrogel, silicic acid, colloidal silica, tetraalkyl orthosilicates, andsilica hydroxides. Gallium, iron, boron and germanium can be added informs corresponding to their aluminum and silicon counterparts. Salts,particularly alkali metal halides such as sodium chloride, can be addedto or formed in the reaction mixture. They are disclosed in theliterature as aiding the crystallization of zeolites while preventingsilica occlusion in the lattice.

The reaction mixture is maintained at an elevated temperature until thecrystals of the zeolite are formed. The temperatures during thehydrothermal crystallization step are typically maintained from about140° C. to about 200° C., preferably from about 150° C. to about 170° C.and most preferably from about 135° C. to about 165° C. Thecrystallization period is typically greater than 1 day and preferablyfrom about 3 days to about 7 days.

The hydrothermal crystallization is conducted under pressure and usuallyin an autoclave so that the reaction mixture is subject to autogenouspressure. The reaction mixture can be stirred during crystallization.

Once the zeolite crystals have formed, the solid product is separatedfrom the reaction mixture by standard mechanical separation techniquessuch as filtration. The crystals are water-washed and then dried, e.g.,at 90° C. to 150° C. for from 8 to 24 hours, to obtain the assynthesized, SSZ-23 zeolite crystals. The drying step can be performedat atmospheric or subatmospheric pressures.

During the hydrothermal crystallization step, the SSZ-23 crystals can beallowed to nucleate spontaneously from the reaction mixture. Thereaction mixture can also be seeded with SSZ-23 crystals both to direct,and accelerate the crystallization, as well as to minimize the formationof undesired aluminosilicate contaminants. If the reaction mixture isseeded with SSZ-23 crystals, the concentration of the organic compoundcan be greatly reduced or eliminated, but it is preferred to have someorganic compound present, e.g., an alcohol.

The synthetic SSZ-23 zeolites can be used as synthesized or can bethermally treated (calcined). Usually, it is desirable to remove thealkali metal cation by ion exchange and replace it with hydrogen,ammonium, or any desired metal ion. The zeolite can be leached withchelating agents, e.g., EDTA or dilute acid solutions, to increase thesilica:alumina mole ratio. The zeolite can also be steamed; steaminghelps stabilize the crystalline lattice to attack from acids. Thezeolite can be used in intimate combination with hydrogenatingcomponents, such as tungsten, vanadium, molybdenum, rhenium, nickel,cobalt, chromium, manganese, or a noble metal, such as palladium orplatinum, for those applications in which ahydrogenation-dehydrogenation function is desired. Typical replacingcations can include metal cations, e.g., rare earth, Group IIA and GroupVIII metals, as well as their mixtures. Of the replacing metalliccations, cations of metals such as rare earth, Mn, Ca, Mg, Zn, Cd, Pt,Pd, Ni, Co, Ti, Al, Sn, Fe and Co are particularly preferred.

The hydrogen, ammonium, and metal components can be exchanged into thezeolite. The zeolite can also be impregnated with the metals, or, themetals can be physically intimately admixed with the zeolite usingstandard methods known to the art. And, the metals can be occluded inthe crystal lattice by having the desired metals present as ions in thereaction mixture from which the SSZ-23 zeolite is prepared.

Typical ion exchange techniques involve contacting the synthetic zeolitewith a solution containing a salt of the desired replacing cation orcations. Although a wide variety of salts can be employed, chlorides andother halides, nitrates, and sulfates are particularly preferred.Representative ion exchange techniques are disclosed in a wide varietyof patents including U.S. Nos. 3,140,249; 3,140,251; and 3,140,253. Ionexchange can take place either before or after the zeolite is calcined.

Following contact with the salt solution of the desired replacingcation, the zeolite is typically washed with water and dried attemperatures ranging from 65° C. to about 315° C. After washing, thezeolite can be calcined i0 in air or inert gas at temperatures rangingfrom about 200° C. to 820° C. for periods of time ranging from 1 to 48hours, or more, to produce a catalytically active product especiallyuseful in hydrocarbon conversion processes.

Regardless of the cations present in the synthesized form of thezeolite, the spatial arrangement of the atoms which form the basiccrystal lattice of the zeolite remains essentially unchanged. Theexchange of cations has little, if any, effect on the zeolite latticestructures.

The SSZ-23 aluminosilicate can be formed into a wide variety of physicalshapes. Generally speaking, the zeolite can be in the form of a powder,a granule, or a molded product, such as extrudate having particle sizesufficient to pass through a 2-mesh (Tyler) screen and be retained on a400-mesh (Tyler) screen. In cases where the catalyst is molded, such asby extrusion with an organic binder, the aluminosilicate can be extrudedbefore drying, or, dried or partially dried and then extruded. Thezeolite can be composited with other materials resistant to thetemperatures and other conditions employed in organic conversionprocesses. Such matrix materials include active and inactive materialsand synthetic or naturally occurring zeolites as well as inorganicmaterials such as clays, silica and metal oxides. The latter may occurnaturally or may be in the form of gelatinous precipitates, sols, orgels, including mixtures of silica and metal oxides. Use of an activematerial in conjunction with the synthetic zeolite, i.e., combined withit, tends to improve the conversion and selectivity of the catalyst incertain organic conversion processes. Inactive materials can suitablyserve as diluents to control the amount of conversion in a given processso that products can be obtained economically without using other meansfor controlling the rate of reaction. Frequently, zeolite materials havebeen incorporated into naturally occurring clays, e.g., bentonite andkaolin. These materials, i.e., clays, oxides, etc., function, in part,as binders for the catalyst. It is desirable to provide a catalysthaving good crush strength, because in petroleum refining the catalystis often subjected to rough handling. This tends to break the catalystdown into powders which cause problems in processing.

Naturally occurring clays which can be composited with the syntheticzeolites of this invention include the montmorillonite and kaolinfamilies, which families include the sub-bentonites and the kaolinscommonly known as Dixie, McNamee, Georgia and Florida clays or others inwhich the main mineral constituent is halloysite, kaolinite, dickite,nacrite, or anauxite. Fibrous clays such as sepiolite and attapulgitecan also be used as supports. Such clays can be used in the raw state asoriginally mined or can be initially subjected to calcination, acidtreatment or chemical modification.

In addition to the foregoing materials, the SSZ-23 zeolites can becomposited with porous matrix materials and mixtures of matrix materialssuch as silica, alumina, titania, magnesia, silica:alumina,silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia,silica-titania, titania-zirconia as well as ternary compositions such assilica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesiaand silica-magnesia-zirconia. The matrix can be in the form of a cogel.

The SSZ-23 zeolites can also be composited with other zeolites such assynthetic and natural faujasites (e.g., X and Y), erionites, andmordenites. They can also be composited with purely synthetic zeolitessuch as those of the ZSM series. The combination of zeolites can also becomposited in a porous inorganic matrix.

SSZ-23 zeolites are useful hydrocarbon conversion reactions. Hydrocarbonconversion reactions are chemical and catalytic processes in whichcarbon containing compounds are changed to different carbon containingcompounds. Examples of hydrocarbon conversion reactions includecatalytic cracking, hydrocracking, and olefin and aromatics formationreactions. The catalysts are useful in other petroleum refining andhydrocarbon conversion reactions such as isomerizing n-paraffins andnaphthenes, polymerizing and oligomerizing olefinic or acetyleniccompounds such as isobutylene and butene-1, reforming, alkylating,isomerizing polyalkyl substituted aromatics (e.g., ortho xylene), anddisproportionating aromatics (e.g., toluene) to provide mixtures ofbenzene, xylenes and higher methylbenzenes. The SSZ-23 catalysts havehigh selectivity, and under hydrocarbon conversion conditions canprovide a high percentage of desired products relative to totalproducts.

SSZ-23 zeolites can be used in processing hydrocarbonaceous feedstocks.Hydrocarbonaceous feedstocks contain carbon compounds and can be frommany different sources, such as virgin petroleum fractions, recyclepetroleum fractions, shale oil, liquefied coal, tar sand oil, and, ingeneral, can be any carbon containing fluid susceptible to zeoliticcatalytic reactions. Depending on the type of processing thehydrocarbonaceous feed is to undergo, the feed can contain metal or befree of metals, it can also have high or low nitrogen or sulfurimpurities. It can be appreciated, however, that in general processingwill be more efficient (and the catalyst more active) the lower themetal, nitrogen, and sulfur content of the feedstock.

SSZ-23 is especially useful as a catalyst in a process for isomerizingone or more xylene isomers in a C₈ aromatic feed to obtain ortho-, meta-and para-xylene in a ratio approaching the equilibrium value. Inparticular, xylene isomerization is used in conjunction with aseparation process to manufacture para-xylene. For example, a portion ofthe para-xylene in a mixed C₈ aromatics stream may be recovered bycrystallization and centrifugation. The mother liquor from thecrystallizer is then reacted under xylene isomerization conditions torestore ortho-, meta-, and para-xylenes to a near equilibrium ratio. Atthe same time, part of the ethylbenzene in the mother liquor isconverted to xylenes or to products which are easily separated bydistillation. The isomerate is blended with fresh feed and the combinedstream is distilled to remove heavy and light by-products. The resultantC₈ aromatics stream is then sent to the crystallizer to repeat thecycle.

Xylene isomerization catalysts are judged on their ability to produce anear equilibrium mixture of xylenes and convert ethylbenzene with verylittle net loss of xylenes. The SSZ-23 type zeolites are especiallyeffective in this regard. Accordingly, an additional aspect of thepresent invention is to provide a hydrocarbon conversion process whichcomprises contacting a C₈ aromatic stream of xylenes, ethylbenzene ormixture thereof, as well as a mixture of ethylbenzenes and otheralkylbenzenes under isomerization conditions with a catalyst comprisingSSZ-23.

The SSZ-23 may conveniently be used as an aggregate in the form ofpellets or extrudates. An inorganic oxide binder such as gamma aluminaor silica may be employed to provide attrition resistance.

In the vapor phase, suitable isomerization conditions include atemperature in the range 500°-1100° F., preferably 600°-1050° F., apressure in the range 0.5-50 atm abs, preferably 1-5 atm abs, and aweight hourly space velocity (WHSV) of 0.1 to 100, preferably 0.5 to 50.Optionally, isomerization in the vapor phase is conducted in thepresence of 3.0 to 30.0 moles of hydrogen per mole of alkylbenzene. Ifhydrogen is used the catalyst should comprise 0.1 to 2.0 wt % of ahydrogenation/dehydrogenation component selected from Group VIII of thePeriodic Table, especially platinum or nickel. By Group VIII metalcomponent is meant the metals and their compounds such as oxides andsulfides.

In the liquid phase, suitable isomerization conditions include atemperature in the range 100°-700° F., a pressure in the range 1-200 atmabs, and a WHSV in the range 0.5-50. Optionally, the isomerization feedmay contain 10 to 90 wt % of a diluent such as toluene,trimethylbenzenes, naphthenes or paraffins.

SSZ-23 can be used to condense lower aliphatic alcohols having 1 to 8carbon atoms to a gasoline boiling point hydrocarbon product comprisingmixed aliphatic and aromatic hydrocarbon. The condensation reactionproceeds at a temperature of about 500° F. to 1000° F., a pressure ofabout 0.5 to 1000 psig and a space velocity of about 0.5 to 50 WHSV. Theprocess disclosed in U.S. Pat. No. 3,984,107 more specifically describesthe process conditions used in this process, which patent isincorporated totally herein by reference.

The catalyst may be in the hydrogen form or may be base exchanged orimpregnated to contain ammonium or a metal cation complement, preferablyin the range of from about 0.05 to 5% by weight. The metal cations thatmay be present include any of the metals of the Groups I through VIII ofthe Periodic Table. However, in the case of Group IA metals the cationcontent should in no case be so large as to effectively inactivate thecatalyst.

The conversion of hydrocarbonaceous feeds can take place in anyconvenient mode, for example, in fluidized bed, moving bed, or fixed bedreactors depending on the types of process desired. The formulation ofthe catalyst particles will vary depending on the conversion process andmethod of operation.

Other reactions which can be performed using the catalyst of thisinvention containing a metal, e.g., platinum, includehydrogenation-dehydrogenation reactions, denitrogenation anddesulfurization reactions.

SSZ-23 can be used in hydrocarbon conversion reactions with active orinactive supports, with organic or inorganic binders, and with andwithout added metals. These reactions are well known to the art, as arethe reaction conditions.

SSZ-23 can also be used as an adsorbent, as a filler in paper, paint,and toothpastes, and as a watersoftening agent in detergents.

The following examples illustrate the preparation of SSZ-23.

EXAMPLES Example 1 Preparation of N,N,N-Trimethyl-1-adamantanammoniumHydroxide (Template A)

Ten (10) grams of 1-adamantanamine (Aldrich) was dissolved in a mixtureof 29 gms tributylamine and 60 mls dimethylformamide. The mixture waschilled in an ice bath.

28.4 Grams of methyl iodide were added dropwise to the chilled solutionwith continuous stirring. After several hours crystals appear. Thereaction was continued overnight and allowed to come to roomtemperature. The crystals were filtered and washed with tetrahydrofuranand then diethyl ether before vacuum drying. Additional product wasobtained by adding enough diethyl ether to the reaction filtrate toproduce two phases and then with vigorous stirring acetone was addeduntil the solution just became one phase. Continued stirring producedcrystallization at which time the solution can be chilled to inducefurther crystallization. The product has a melting point near 300° C.(decomp.) and the elemental analyses and NMR are consistent with theknown structure. The vacuum-dried iodide salt was then ion-exchangedwith ion-exchange resin AG 1×8 (in molar excess) to the hydroxide form.The exchange was performed over a column or more preferably by overnightstirring of the resin beads and the iodide salt in an aqueous solutiondesigned to give about a 0.5 molar solution of the organic hydroxide.This produces Template A.

Example 2 Preparation of N,N,N-Trimethyl-2-adamantan-ammonium Hydroxide(Template B)

Five grams of 2-adamantanone (Aldrich Chemical Co.) was mixed with 2.63gms of formic acid (88%) and 4.5 gms of dimethyl formamide. The mixturewas then heated in a pressure vessel for 16 hours at 190° C. Care shouldbe taken to anticipate the increase in pressure the reaction experiencesdue to CO₂ evolution. The reaction was conveniently carried out in aParr 4748 reactor with teflon liner. The workup consists of extractingN,N dimethyl-2-adamantamine from a basic (pH=12) aqueous solution withdiethyl ether. The various extracts were dried with Na₂ SO₄ the solventremoved and the product taken up in ethyl acetate. An excess of methyliodide was added to a cooled solution which was then stirred at roomtemperature for several days. The crystals were collected and washedwith diethyl ether to give N,N,N trimethyl-2adamantammonium iodide. Theproduct was checked by micro-analysis for C, H, and N. The conversion tothe hydroxide form was carried out analogously to Template A above.

Example 3

0.12 Grams of Al₂ (SO₄)₃. 18H₂ O were dissolved in a solution of 0.26gms KOH (solid) in 16 ml of a 0.26 molar template hydroxide preparedaccording to Example 1. 1.21 Grams of Cabosil M5 was slowly added withstirring and the contents on the ensuing thin gel were placed in theTeflon liner of Parr 4745 reactor. The reactor was placed on a rotatingspit inside a Blue M oven and rotated at 30 RPM while heating thereaction to 175° C. for 7 days. Upon cooling, the sample and filtration,a fine white solid, was collected. By X-ray diffraction, the product waszeolite SSZ-23 with a trace of zeolite SSZ-13 as impurity. Using the BETmethod for nitrogen absorption and desorption, the surface area ofzeolite after calcination to 1100° F., ion-exchanged with NH₄ NO₃ (4times) and recalcining at 1000° F. (to yield the hydrogen form), wasapproximately 400 cm^(2/) gm with a micropore volume of about 0.16cc/gm. In the as-made form, the zeolite SSZ-23 shows C/N⁺ ratios closeto 13, the ratio in the template, and the organic content accounts forabout 15% of the product mass indicating substantial pore filling by thetemplate during synthesis.

Example 4

0.12 Grams of Al₂ (SO₄)₃. 18H₂ 0, 0.26 gms of KOH (solid) and 4 ml of a1 molar solution of the template hydroxide of Example 1 were dissolvedin 12 mls H₂ O. 1.20 Grams of Cabosil M5 were blended into the solutionand the mixture was heated and worked up as in Example 3. The product byX-ray diffraction was zeolite SSZ-23 with quartz as an impurity.

Example 5

0.087 Grams of KOH (solid), 0.06 gms of Al₂ (SO₄)₃. 18H ₂ O and 5 gramsof a 0.74 molar solution of the template hydroxide of Example 1 weredissolved in 4 ml of H₂ O containing 4 micromoles of methylene Blue Dye.0.60 Grams of Cabosil M5 was stirred in. The reaction was sealed in thesame Parr reactor as Example 3 and heated for 7 days at 30 RPM, but withthe reaction temperature reduced to 160° C. The cooled reaction wasopened and the fine white solids are recovered by filtration. Afterworking with copious quantities of distilled water, the product wasair-dried overnight. After drying at 100° C. analysis by the X-raydiffraction pattern, as demonstrated in Table 3 below, shows thematerial to be pure SSZ-23. The ratio of reactants in this run were:

Si:O₂ /Al₂ O₃ =100

KOH/SiO₂ =0.13

TEMPLATE OH⁻ /SiO₂ =0.37

H₂ O/SiO₂ =44

net OH⁻ /SiO₂ =0.45

The most frequently encountered impurity in the preparation of zeoliteSSZ-23 can be zeolite SSZ-13. To minimize the formation of the latterzeolite, I have found it advantageous to (a) exclude Na⁺ ion from thepreparation and (b) to use methylene Blue at a level of methyleneBlue/Al₂ O₃ =4.4×10⁻². The methylene Blue is known to inhibit thenucleation of certain zeolite phases (Whittam et al. British Patent No.1,450,411) and because zeolite SSZ-13 is a high silica chabazitestructure, this particular dye seems to be effective in preventing itscrystallization in zeolite SSZ-23 syntheses.

                  TABLE 3                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        8.18           10.81   100                                                    8.60           10.28   27                                                     9.52           9.29    33                                                     10.57          8.37    43                                                     14.53          6.10    30                                                     15.57          5.69    27                                                     17.63          5.03    37                                                     18.07          4.91    43                                                     18.56          4.78    80                                                     19.00          4.67    13                                                     19.67          4.51    60                                                     20.08          4.42    60                                                     20.33          4.37    20                                                     20.67          4.30    43                                                     21.13          4.205   10                                                     21.55          4.123   90                                                     22.18          4.008   43                                                     22.47          3.957   33                                                     22.75          3.909   57                                                     23.35          3.810   33                                                     23.72          3.751   20                                                     24.00          3.708   10                                                     24.49          3.635   27                                                     24.91          3.574   43                                                     25.54          3.488   10                                                     26.62          3.349   27                                                     26.91          3.313   23                                                     27.37          3.258   20                                                     27.86          3.202   20                                                     28.31          3.152   13                                                     28.60          3.121   17                                                     29.17          3.061   10                                                     29.54          3.024   17                                                     30.05          2.974   10                                                     30.63          2.919   23                                                     ______________________________________                                    

Example 6

The same reactants were used as in Example 5 but changes were made toyield the following ratios of reactants:

SiO₂ /Al₂ O₃ =120

KOH/SiO₂ =0.22

Template OH⁻ /SiO² =0.22

H₂ O/ SiO₂ =44

OH⁻ /SiO₂ =0.38

Methylene Blue/Al₂ O₃ =1×10⁻³

The reaction mixture was heated as in Example 5 and worked up in ananalogous fashion. The crystalline product was zeolite SSZ-23 with atridymite-like silica impurity. In general, zeolite SSZ-23 crystallizesin discs of about 1-6μ length.

Example 7

In this example the KOH of Example 5 was replaced by 0.047 gms of NaOH.The remaining reagents of Example 5 were the same. The reaction was runand worked up as in Example 5 except the run time was 6 days. Thezeolite product was again SSZ-23.

Example 8

Another run was set up and run as in Example 5. Here, the alkali cationwas rubidium and it was supplied by using 0.17 gms of a 50% solution ofrubidium hydroxide (Alfa Inorganics). The crystalline product wasSSZ-23.

Example 9

This run uses 0.25 gms of 50% CsOH as the alkali source. Using the samerun conditions as Example 5 the product was SSZ-23.

Example 10

In this reaction the starting SiO₂ /Al₂ O₃ ratio was 50, so theresulting ratio in the zeolite product will be lower than in Examples 5to 9 above (which had initial SiO₂ /Al₂ O₃ values of 120). Once againthe reaction was carried out in a Parr 4745 reactor. 4.15 Grams ofTemplate B of Example 2 (0.72 M) was mixed with 5 mls water, 0.59 gms of50% rubidium hydroxide and 2.36 gms of Ludox AS-30 colloidal silica.After stirring the reagents with a stir bar as above, 0.78 gms of Nalco1SJ612 colloidal silica with alumina dispersed on it was blended in. Thereactor was sealed, loaded onto the spit and heated at 175° C. for tendays while rotating at 30 RPM with the stir bar still in the reactor.The resulting product after the appropriate workup was SSZ-23.

Example 11

This example illustrates the synthesis of SSZ-23 from a mixture withSiO₂ /Al₂ O₃ =200. Using the same equipment including the pea shapestirrer as in the preceding examples, the following reagents were mixed:5.6 ml of Template A (0.70 M), 0.065 gms of KOH(s), and 0.06 gms of Al₂(SO₄)₃. 18 H₂ O was dissolved in 10.2 ml H₂ O. Then 1.20 gms of CabosilM5 were added. The reaction was run for 6 days at 160° C. with 30 RPMagitation. The product was crystalline SSZ-23.

Example 12

SSZ-23 can be formed in an essentially aluminum free system. 54.4 Gramsof Template A (0.72M), and 0.65 gms of KOH(s) were dissolved in 110 mlH₂ O. 12.71 Grams of Cabosil M5 were added and stirred. The reactionmixture was loaded into a 600 cc Parr stirred reactor and heated at 160°C. for 6 days with 100 RPM stirring. The product upon workup wascrystalline SSZ-23. The X-ray diffraction pattern of this product isgiven in Table 4 below.

                  TABLE 4                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        8.12           10.89   100                                                    8.56           10.33   60                                                     9.47           9.34    75                                                     10.53          8.40    40                                                     14.48          6.12    25                                                     15.56          5.70    25                                                     17.58          5.04    50                                                     18.02          4.92    30                                                     18.51          4.79    80                                                     18.93          4.69    25                                                     19.62          4.52    100                                                    20.04          4.43    100                                                    20.32          4.37    15                                                     20.63          4.305   30                                                     21.04          4.222   10                                                     21.50          4.133   100                                                    22.13          4.017   60                                                     22.43          3.964   40                                                     22.68          3.920   80                                                     23.31          3.816   25                                                     23.67          3.759   20                                                     23.93          3.719   10                                                     24.47          3.638   20                                                     24.83          3.586   45                                                     25.50          3.493   10                                                     26.60          3.351   25                                                     26.86          3.319   20                                                     27.33          3.263   25                                                     27.83          3.206   15                                                     28.29          3.155   10                                                     28.55          3.126   25                                                     29.15          3.063   10                                                     29.48          3.030   15                                                     30.00          2.979   10                                                     30.55          2.926   35                                                     ______________________________________                                    

Example 13

Six grams of a 0.65 M solution of Template B were dissolved in 10 ml H₂O along with 0.06 grams of Al₂ (SO₄)₃. 18 H₂ O and 0.11 gms of KOH(s).1.20 Grams of Cabosil M5 are added and the reaction was run as inExample 11, however, the product was worked up after 15 days with 30 RPMstirring. The product was once again SSZ-23.

Example 14

A. The crystalline products of Examples 5, 10 and 12 were subjected tocalcination as follows. The samples were heated in a muffle furnace fromroom temperature up to 540° C. at a steadily increasing rate over a2-hour period. The samples were maintained at 540° C. for four morehours and then taken up to 600° C. for an additional four hours. A 50/50mixture of air and nitrogen was passed over the zeolites at a rate of 20standard cubic feet per minute during heating. The calcined product ofExamples 12 and 5 had representative X-ray diffraction patterns asindicated in Tables 5 and 6, respectively.

                  TABLE 5                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        8.16           10.84   80                                                     8.50           10.40   32                                                     9.43           9.38    100                                                    10.56          8.38    38                                                     13.28          6.67    7                                                      13.85          6.39    5                                                      17.78          4.99    7                                                      18.59          4.77    19                                                     19.59          4.53    16                                                     20.03          4.433   9                                                      21.58          4.118   14                                                     22.12          4.019   8                                                      22.55          3.943   11                                                     24.60          3.619   6                                                      24.92          3.573   8                                                      26.65          3.345   8                                                      28.48          3.134   8                                                      ______________________________________                                    

                  TABLE 6                                                         ______________________________________                                        2 θ      d/n     I/I.sub.o                                              ______________________________________                                        7.94           11.41   22                                                     8.07           10.96   44                                                     8.17           10.82   100                                                    8.50           10.40   16                                                     9.47           9.34    76                                                     10.56          8.38    49                                                     13.27          6.67    9                                                      13.88          6.38    7                                                      17.78          4.99    8                                                      18.57          4.78    21                                                     19.66          4.515   12                                                     20.08          4.422   8                                                      21.58          4.118   15                                                     22.12          4.019   7                                                      22.56          3.941   11                                                     24.60          3.619   7                                                      24.89          3.577   8                                                      26.60          3.351   7                                                      28.60          3.132   5                                                      ______________________________________                                    

B. Ion-exchange of the calcined materials from A. above of Examples 5,10 and 12 was carried out using NH₄ NO₃ to convert the zeolites fromtheir K form to NH₄ and then eventually H form. Typically the same massof NH₄ NO₃ as zeolite was slurried into H₂ O at ratio of 50/1 H₂ O tozeolite. The exchange solution was heated at 100° C. for two hours andthen filtered. This process was repeated four times. Finally, after thelast exchange the zeolite was washed several times with H₂ O and dried.A repeat calcination as in A. above was carried out but without thefinal treatment at 600° C. This produces the H form of the zeolites.

Example 15 Constraint Index Determination

0.25 Grams of the hydrogen form of the zeolite of Examples 5, 10 and 12(after treatment according to Example 14, parts A. and B.) were packedseparately into a 3/8" stainless steel tube with alundum on both sidesof the zeolite bed. A Lindburg furnace was used to heat the reactortube. Helium was introduced into the reactor tube at 10 cc/min. andatmospheric pressure. The reactor was taken to 250° F. for 40 min. andthen raised to 800° F. Once temperature equilibration was achieved a50/50, w/w feed of n-hexane and 3-methylpentane was introduced into thereactor at a rate of 0.62 cc/hr. Feed delivery was made via syringepump. Direct sampling onto a gas chromatograph began after 10 minutes offeed introduction. Constraint Index values were calculated from gaschromatographic data using methods known in the art.

    ______________________________________                                        Example No.                                                                            C.I.     Conversion at 10 min.                                                                        Temp. °F.                             ______________________________________                                        5        4        9%             800                                          12       --       0%             800                                          10       2        16%            800                                          ______________________________________                                    

Example 16

The hydrogen form of the SSZ-23 zeolite was tested as catalyst forxylene isomerization. A portion of the HSSZ-23 powder was pelleted,crushed and sieved to obtain 20-40 mesh granules, which were thencalcined for four hours at 1000° F. One gram of the calcined materialwas charged to a 3/16-inch I.D. tubular microreactor heated by anelectric furnace. The catalyst bed was heated to 850° F. in flowinghelium. The helium was then replaced with a mixed xylene feed. The feedcomposition and reactor effluent were analyzed by gas chromatography.The test results are shown in Table 7. The HSSZ-23 catalyst produced anear equilibrium mixture of xylene isomers with excellent ethylbenzeneconversion and very little xylene loss.

                  TABLE 7                                                         ______________________________________                                        Xylene Isomerization Over HSSZ-23                                             ______________________________________                                        Hours on Stream   2-4     8-23                                                Temperature, °F.                                                                         850     825                                                 WHSV              5       5                                                   Pressure, psig    24      26                                                  ______________________________________                                        Composition, Wt %                                                                              Feed     Products                                            ______________________________________                                        non-aromatics    0.44     1.60    1.40                                        benzene          0.00     3.95    2.70                                        toluene          1.34     2.65    2.06                                        ethylbenzene     9.76     4.32    6.04                                        p-xylene         9.61     19.69   19.50                                       m-xylene         53.99    44.11   44.79                                       o-xylene         23.10    20.45   20.68                                       heavy aromatics  1.77     3.25    2.84                                        Percent EB conversion     55.7    38.1                                        Percent Xylene Loss       2.5     1.7                                         p-xyl & approach to equil.                                                                              100.2   96.4                                        ______________________________________                                    

Example 17

The same catalyst as used in Example 16 above was also tested formethanol conversion. 0.5 Gram of catalyst was packed in a 3/8-inchstainless steel reactor tube which was heated to 100° F. in a furnace.The reactor was brought back down to 800° F. in a stream of dry helium.Methanol was introduced into the reactor at a rate of 1.3 cc/hr and ahelium flow rate of 20 cc/hr. Initial conversion was 100% and thehydrocarbon products are given in Table 8.

                  TABLE 8                                                         ______________________________________                                        Methanol Conversion over HSSZ-23 at 10 Minutes on Stream                      Product       Weight Percent                                                  ______________________________________                                        Methane       3.4                                                             Ethylene      19.9                                                            Ethane        2.0                                                             Propylene     19.4                                                            Propane       20.1                                                            C.sub.4 Olefins                                                                             10.4                                                            C.sub.4 Paraffins                                                                           9.7                                                             C.sub.5       5.4                                                             Benzene       1.3                                                             Toluene       4.0                                                             P-xylene      4.5                                                             ______________________________________                                    

What is claimed is:
 1. A zeolite having a mole ratio of an oxideselected from silicon oxide, germanium oxide and mixtures thereof to anoxide selected from aluminum oxide, gallium oxide, iron oxide, boronoxide and mixtures thereof greater than about 50:1, and having the X-raydiffraction lines of Table
 1. 2. A zeolite having a composition, assynthesized and in the anhydrous state, in terms of mole ratios ofoxides as follows: (0.1 to 3.0)Q₂ O:(0.1 to 2.0)M₂ O:W₂ O₃ : (greaterthan 50) YO₂ wherein M is an alkali metal cation, W is selected fromaluminum, gallium, iron, boron and mixtures thereof, Y is selected fromsilicon, germanium and mixtures thereof, Q is an adamantane quaternaryammonium ion and having the X-ray diffraction lines of Table
 1. 3. Thezeolite according to claim 2 wherein W is aluminum and Y is silicon. 4.A zeolite prepared by thermally treating the zeolite of claim 3 at atemperature from about 200° C. to 820° C.
 5. A zeolite according toclaim 2 wherein the adamantane quaternary ammonium ion is derived froman adamantane compound of the formula: ##STR3## wherein each of Y₁ Y₂and Y₃ independently is lower alkyl and A⊖ is an anion which is notdetrimental to the formation of the zeolite; and each of R₁, R₂ and R₃independently is hydrogen, or lower alkyl; or ##STR4## wherein each ofR₄, R₅ and R₆ independently is hydrogen or lower alkyl; each of Y₁, Y₂and Y₃ independently is lower alkyl; and A⊖ is an anion which is notdetrimental to the formation of the zeolite.
 6. A zeolite according toclaim 5 wherein in formula (a) each of Y₁, Y₂ and Y₃ independently ismethyl or ethyl; A⊖ is OH or halogen; and each of R₁, R₂, and R₃ ishydrogen; and in formula (b) each of Y₁, Y₂ and Y₃ independently ismethyl or ethyl; A⊖ is OH, or halogen; and each of R₄, R₅ and R₆ ishydrogen.
 7. A zeolite according to claim 6 wherein Y₁, Y₂ and Y₃ arethe same and each is methyl; and A⊖ is OH, or I.
 8. A zeolite accordingto claim 1 or 2 which has undergone ion exchange with hydrogen,ammonium, rare earth metal, Group IIA metal, or Group VIII metal ions.9. A zeolite according to claim 1 or 2 wherein rare earth metals, GroupIIA metals, or Group VIII metals are occluded in the zeolite.
 10. Azeolite composition, comprising the zeolite of claim 1 or 2 and aninorganic matrix.
 11. A zeolite having a mole ratio of an oxide selectedfrom silicon oxide, germanium oxide and mixtures thereof to an oxideselected from aluminum oxide gallium oxide, iron oxide, boron oxide andmixtures thereof of from about 50:1 to 1500:1, and having the X-raydiffraction lines of Table
 1. 12. A zeolite having a composition, assynthesized and in the anhydrous state, in terms of mole ratios ofoxides as follows: (0.1 to 3.0)Q₂ O:(0.1 to 2.0)M₂ O:W₂ O₃ : (50:1 to1500:1) YO₂ wherein M is an alkali metal cation, W is selected fromaluminum, gallium, iron, boron and mixtures thereof, Y is selected fromsilicon, germanium and mixtures thereof, Q is an adamantane quaternaryammonium ion and having the X-ray diffraction lines of Table 1.